DB2 Version 9.7 for Linux, UNIX, and Windows

hash_join_overflows - Hash Join Overflows monitor element

The number of times that hash join data exceeded the available sort heap space.

Table 1. Snapshot Monitoring Information
Snapshot Level	Logical Data Grouping	Monitor Switch
Database	dbase	Basic
Application	appl	Basic

For snapshot monitoring, this counter can be reset.

Table 2. Event Monitoring Information
Event Type	Logical Data Grouping	Monitor Switch
Database	event_db	-
Connection	event_conn	-

Usage: At the database level, if the value of hash_join_small_overflows is greater than 10% of this hash_join_overflows, then you should consider increasing the sort heap size. Values at the application level can be used to evaluate hash join performance for individual applications.